1. Field of the Invention
This invention relates to electrical pickups adapted for use with multistringed metal musical instruments and, more particularly, relates to an electromagnetic pickup adapted for use with a multistringed musical instrument having strings formed of a ferromagnetic material to produce an output signal, the amplitude of frequency of which is representative of the vibrations of a ferromagnetic string. In the preferred embodiment, a electromagnetic pickup is adapted for use with a guitar.
2. Description of the Prior Art
The use of electrical pickups for stringed musical instruments having ferromagnetic strings is well known in the art. One electromagnetic pickup for stringed musical instruments is described in U.S. Pat. No. 4,220,069 and comprises a pickup assembly utilizing a single bar magnet, a coil means and at least one metallic, unmagnetized pole piece operationally associated with the strings of an instrument. Other single-cell magnetic pickup devices for stringed musical instruments are disclosed in U.S. Pat. Nos. 4,026,178; 4,050,341; 4,133,243; and 4,320,681.
The use of an electromagnetic pickup having a plurality of coils which are positioned in a side-by-side relationship and having permanent magnet members is discussed in U.S. Pat. Nos. 4,283,982; 3,983,777; 3,983,778; and 3,962,946.
An electromagnetic pickup having a coil formed by first and second windings wound in parallel on the same coil bobbin, one on top of the other, is disclosed in U.S. Pat. No. 3,711,619.
An electromagnetic pickup having two coils, each of which have openings in the center thereof and wherein the aligned coils are divided and spaced apart by a magnetic pole piece and wherein the aligned openings have a permanent magnet member located therein wherein one edge of the permanent magnet member is adapted to be positioned adjacent strings formed of ferromagnetic materials on a multistringed instrument, is disclosed in U.S. Pat. No. 3,902,394.
An electromagnetic pickup having coils arranged in a similar manner to the coils of U.S. Pat. No. 3,902,394 but wherein two separate rectangular-shaped permanent magnet members are positioned one on each side of and coniguous the magnetic pole piece and with a ferromagnetic material in the form of a plurality of screws located in the openings of the coil and threaded into and through the magnetic pole piece is disclosed in U.S. Pat. No. 3,916,751.
A single pickup frequency control for a stringed instrument wherein the pickup comprises a bar magnet, the poles of which are situated at the top and the bottom faces thereof and wherein a divider surrounds the magnet transversely of and parallel with the two polar faces of the magnet and wherein the wire coils surround the magnet on each side of the divider plate with the coils so connected that the electrical path of one coil is clockwise while the electrical path of the other coil is counterclockwise is disclosed in U.S. Pat. No. 3,657,461.
Electrical pickups manufactured and sold by Gibson Guitar Company in the early 1960s had an upper coil and a lower coil divided by a horizontal permanent magnet with the vertically extending openings in the coil completely filled with an iron load wherein one of the coils having the iron load was positioned in a spaced relationship from ferromagnetic strings on a multistringed instrument.